From patchwork Thu Apr 10 17:17:23 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= X-Patchwork-Id: 14047041 Received: from smtp-bc08.mail.infomaniak.ch (smtp-bc08.mail.infomaniak.ch [45.157.188.8]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8053F1F09BF for ; Thu, 10 Apr 2025 17:25:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.157.188.8 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744305918; cv=none; b=N4zDVmWhtSjGyVvl/G9Rlkb4c7QkWMZ5O6yr6UCGCN2kywbfMgOGjImqFtH/+SmB3AksF9imEs8QjQauBl7IcqzU6pZ9e4Ja1tP6I8AjoD/BSxKybTky47OPT7epYwrW7w9BZMVcXEH/s12Fxavh2xBgYBJsSDdneO5f+3iC9Lw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744305918; c=relaxed/simple; bh=IzSTGxrRRiCItD0srLShw+8nST5LMas3YolXKiNwVeg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=EZJlNs38mqbTKR+pTaxRE+mY7LAX9eyoSWjDDT1bteKdqeqVk/hQJJh7ZYvj9RDQH3jRTDqvT64pEw1ZaQGQTXE/XmwFJwmpjYqIl5CvIgLS1qpKf1Ah9ePUGvtzZnlX5Jc8NHbsNGIQw28Nf+0w4+FzFQPoNiKaZ7Ktzk5C3I0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=digikod.net; spf=pass smtp.mailfrom=digikod.net; dkim=pass (1024-bit key) header.d=digikod.net header.i=@digikod.net header.b=QA+15piz; arc=none smtp.client-ip=45.157.188.8 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=digikod.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=digikod.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=digikod.net header.i=@digikod.net header.b="QA+15piz" Received: from smtp-3-0001.mail.infomaniak.ch (unknown [IPv6:2001:1600:4:17::246c]) by smtp-3-3000.mail.infomaniak.ch (Postfix) with ESMTPS id 4ZYRMl0BNVzZ39; Thu, 10 Apr 2025 19:17:39 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=digikod.net; s=20191114; t=1744305458; bh=xINIg+qaeGf/DRdagSjHiaFjd/ETAsOMFZSkkPcQ1go=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QA+15pizxrECElwJnfvDtG8EzbOcEDHqaJDD8i/gXHeZPteqA7Nk4UX+J7a0/RNZN HH8JY8YmrNG+vW7KCM9NdUo0SrVhpsOLqN6aOy2J3So/VRrrKLQDC0DO7RbU91X6IC f4rJ11gmZT9cnE7qzIA8drDJRwB8dSDT/5G7VNXg= Received: from unknown by smtp-3-0001.mail.infomaniak.ch (Postfix) with ESMTPA id 4ZYRMk4BpBzV6m; Thu, 10 Apr 2025 19:17:38 +0200 (CEST) From: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= To: =?utf-8?q?G=C3=BCnther_Noack?= Cc: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= , linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, Christian Brauner , Paul Moore Subject: [PATCH v1 3/3] selftests/landlock: Add PID tests for audit records Date: Thu, 10 Apr 2025 19:17:23 +0200 Message-ID: <20250410171725.1265860-3-mic@digikod.net> In-Reply-To: <20250410171725.1265860-1-mic@digikod.net> References: <20250410171725.1265860-1-mic@digikod.net> Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Infomaniak-Routing: alpha Add audit.thread tests to check that the PID tied to a domain is not a thread ID but the thread group ID. These new tests would not pass without the previous TGID fix. Extend matches_log_domain_allocated() to check against the PID that created the domain. Test coverage for security/landlock is 93.6% of 1524 lines according to gcc/gcov-14. Cc: Christian Brauner Cc: Günther Noack Cc: Paul Moore Signed-off-by: Mickaël Salaün --- tools/testing/selftests/landlock/audit.h | 21 ++- tools/testing/selftests/landlock/audit_test.c | 127 +++++++++++++++++- tools/testing/selftests/landlock/fs_test.c | 3 +- 3 files changed, 141 insertions(+), 10 deletions(-) diff --git a/tools/testing/selftests/landlock/audit.h b/tools/testing/selftests/landlock/audit.h index b9054086a0c9..18a6014920b5 100644 --- a/tools/testing/selftests/landlock/audit.h +++ b/tools/testing/selftests/landlock/audit.h @@ -300,15 +300,22 @@ static int audit_match_record(int audit_fd, const __u16 type, return err; } -static int __maybe_unused matches_log_domain_allocated(int audit_fd, +static int __maybe_unused matches_log_domain_allocated(int audit_fd, pid_t pid, __u64 *domain_id) { - return audit_match_record( - audit_fd, AUDIT_LANDLOCK_DOMAIN, - REGEX_LANDLOCK_PREFIX - " status=allocated mode=enforcing pid=[0-9]\\+ uid=[0-9]\\+" - " exe=\"[^\"]\\+\" comm=\".*_test\"$", - domain_id); + static const char log_template[] = REGEX_LANDLOCK_PREFIX + " status=allocated mode=enforcing pid=%d uid=[0-9]\\+" + " exe=\"[^\"]\\+\" comm=\".*_test\"$"; + char log_match[sizeof(log_template) + 10]; + int log_match_len; + + log_match_len = + snprintf(log_match, sizeof(log_match), log_template, pid); + if (log_match_len > sizeof(log_match)) + return -E2BIG; + + return audit_match_record(audit_fd, AUDIT_LANDLOCK_DOMAIN, log_match, + domain_id); } static int __maybe_unused matches_log_domain_deallocated( diff --git a/tools/testing/selftests/landlock/audit_test.c b/tools/testing/selftests/landlock/audit_test.c index 815c0f03e1fb..cfc571afd0eb 100644 --- a/tools/testing/selftests/landlock/audit_test.c +++ b/tools/testing/selftests/landlock/audit_test.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -104,7 +105,8 @@ TEST_F(audit, layers) matches_log_signal(_metadata, self->audit_fd, getppid(), &denial_dom)); EXPECT_EQ(0, matches_log_domain_allocated( - self->audit_fd, &allocated_dom)); + self->audit_fd, getpid(), + &allocated_dom)); EXPECT_NE(denial_dom, 1); EXPECT_NE(denial_dom, 0); EXPECT_EQ(denial_dom, allocated_dom); @@ -156,6 +158,126 @@ TEST_F(audit, layers) EXPECT_EQ(0, close(ruleset_fd)); } +struct thread_data { + pid_t parent_pid; + int ruleset_fd, pipe_child, pipe_parent; +}; + +static void *thread_audit_test(void *arg) +{ + const struct thread_data *data = (struct thread_data *)arg; + uintptr_t err = 0; + char buffer; + + /* TGID and TID are different for a second thread. */ + if (getpid() == gettid()) { + err = 1; + goto out; + } + + if (landlock_restrict_self(data->ruleset_fd, 0)) { + err = 2; + goto out; + } + + if (close(data->ruleset_fd)) { + err = 3; + goto out; + } + + /* Creates a denial to get the domain ID. */ + if (kill(data->parent_pid, 0) != -1) { + err = 4; + goto out; + } + + if (EPERM != errno) { + err = 5; + goto out; + } + + /* Signals the parent to read denial logs. */ + if (write(data->pipe_child, ".", 1) != 1) { + err = 6; + goto out; + } + + /* Waits for the parent to update audit filters. */ + if (read(data->pipe_parent, &buffer, 1) != 1) { + err = 7; + goto out; + } + +out: + close(data->pipe_child); + close(data->pipe_parent); + return (void *)err; +} + +/* Checks that the PID tied to a domain is not a TID but the TGID. */ +TEST_F(audit, thread) +{ + const struct landlock_ruleset_attr ruleset_attr = { + .scoped = LANDLOCK_SCOPE_SIGNAL, + }; + __u64 denial_dom = 1; + __u64 allocated_dom = 2; + __u64 deallocated_dom = 3; + pthread_t thread; + int pipe_child[2], pipe_parent[2]; + char buffer; + struct thread_data child_data; + + child_data.parent_pid = getppid(); + ASSERT_EQ(0, pipe2(pipe_child, O_CLOEXEC)); + child_data.pipe_child = pipe_child[1]; + ASSERT_EQ(0, pipe2(pipe_parent, O_CLOEXEC)); + child_data.pipe_parent = pipe_parent[0]; + child_data.ruleset_fd = + landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0); + ASSERT_LE(0, child_data.ruleset_fd); + + /* TGID and TID are the same for the initial thread . */ + EXPECT_EQ(getpid(), gettid()); + EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)); + ASSERT_EQ(0, pthread_create(&thread, NULL, thread_audit_test, + &child_data)); + + /* Waits for the child to generate a denial. */ + ASSERT_EQ(1, read(pipe_child[0], &buffer, 1)); + EXPECT_EQ(0, close(pipe_child[0])); + + /* Matches the signal log to get the domain ID. */ + EXPECT_EQ(0, matches_log_signal(_metadata, self->audit_fd, + child_data.parent_pid, &denial_dom)); + EXPECT_NE(denial_dom, 1); + EXPECT_NE(denial_dom, 0); + + EXPECT_EQ(0, matches_log_domain_allocated(self->audit_fd, getpid(), + &allocated_dom)); + EXPECT_EQ(denial_dom, allocated_dom); + + /* Updates filter rules to match the drop record. */ + set_cap(_metadata, CAP_AUDIT_CONTROL); + EXPECT_EQ(0, audit_filter_drop(self->audit_fd, AUDIT_ADD_RULE)); + EXPECT_EQ(0, audit_filter_exe(self->audit_fd, &self->audit_filter, + AUDIT_DEL_RULE)); + clear_cap(_metadata, CAP_AUDIT_CONTROL); + + /* Signals the thread to exit, which will generate a domain deallocation. */ + ASSERT_EQ(1, write(pipe_parent[1], ".", 1)); + EXPECT_EQ(0, close(pipe_parent[1])); + ASSERT_EQ(0, pthread_join(thread, NULL)); + + EXPECT_EQ(0, setsockopt(self->audit_fd, SOL_SOCKET, SO_RCVTIMEO, + &audit_tv_dom_drop, sizeof(audit_tv_dom_drop))); + EXPECT_EQ(0, matches_log_domain_deallocated(self->audit_fd, 1, + &deallocated_dom)); + EXPECT_EQ(denial_dom, deallocated_dom); + EXPECT_EQ(0, setsockopt(self->audit_fd, SOL_SOCKET, SO_RCVTIMEO, + &audit_tv_default, sizeof(audit_tv_default))); +} + FIXTURE(audit_flags) { struct audit_filter audit_filter; @@ -270,7 +392,8 @@ TEST_F(audit_flags, signal) /* Checks domain information records. */ EXPECT_EQ(0, matches_log_domain_allocated( - self->audit_fd, &allocated_dom)); + self->audit_fd, getpid(), + &allocated_dom)); EXPECT_NE(*self->domain_id, 1); EXPECT_NE(*self->domain_id, 0); EXPECT_EQ(*self->domain_id, allocated_dom); diff --git a/tools/testing/selftests/landlock/fs_test.c b/tools/testing/selftests/landlock/fs_test.c index f819011a8798..73729382d40f 100644 --- a/tools/testing/selftests/landlock/fs_test.c +++ b/tools/testing/selftests/landlock/fs_test.c @@ -5964,7 +5964,8 @@ TEST_F(audit_layout1, refer_handled) EXPECT_EQ(EXDEV, errno); EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd, "fs\\.refer", dir_s1d1)); - EXPECT_EQ(0, matches_log_domain_allocated(self->audit_fd, NULL)); + EXPECT_EQ(0, + matches_log_domain_allocated(self->audit_fd, getpid(), NULL)); EXPECT_EQ(0, matches_log_fs(_metadata, self->audit_fd, "fs\\.refer", dir_s1d3));